Universal mineral separator

ABSTRACT

In accordance with the present invention, a pneumatic particle separator includes a base member formed with an elongated lumen. Also formed on the base member for fluid communication with the lumen are, in order, an air flow injection channel, the lumen, a diverter, and an n-number of type channels. Further, a particle injection channel is connected in fluid communication with the air flow injection channel. In this combination, when an air flow is established through the air flow injection channel and the lumen, particles are drawn by venturi action from the particle injection channel for single file transit through the lumen for analysis. A subsequent pneumatic diversion through the diverter then provides an exit for each particle from the base member through a preselected type channel for collection. The analysis performed in the lumen is used for an assay report.

FIELD OF THE INVENTION

The present invention pertains generally to geological assays, mineralprocessing, and particle analysis and sorting techniques. Moreparticularly, the present invention pertains to field assay units thatanalyze samples containing powders or pre-crushed rock particles. Thepresent invention is particularly, but not exclusively, useful as afield assay unit which pneumatically aligns all particles of the samplein single file during transport through the unit for an independentevaluation of each individual particle as to size and composition type.

BACKGROUND OF THE INVENTION

An assay involves the testing and examination of sample material todetermine its composition and the quality of its ingredients. In thecase of metals and ores it is sometimes necessary that the assay be doneon site where the metal or the ore is located. In any event, the assayis preferably accomplished quickly, accurately and efficiently.

Heretofore, preparing an assay of an ore/mineral sample in real time hasbeen quite labor intensive and has been limited by several operationalconsiderations such as sampling and detection limitations. In general,it is first necessary to crush the ore/mineral into particles for bulkprocessing. Samples of the crushed material are then retrieved. Next,the samples are analyzed. As a practical matter, the specifics for abulk analysis of samples are varied and can be quite different. Forexample, U.S. Pat. No. 8,151,632 for a “Method for defining elementcontent and/or mineral content” discloses a mineral separation processin which a sample of crushed particles is bulk analyzed using a grainsize analysis operation.

In the event, all ore/mineral assays have, as their primary objective, adetermination of the mineral composition in the ore sample and itsquality. The present invention, however, recognizes that a bulk analysisof ore/mineral samples for this purpose can be cumbersome, destructiveand expensive. Further, the present invention recognizes that ananalysis of an ore/mineral sample on a particle-by-particle basisprovides for more precise measurements and more accurate results.

With the above in mind, it is an object of the present invention toprovide a device and method for separating particles according to theircomposition, wherein each individual particle in a sample isindividually evaluated and categorized, on a particle-by-particle basis,for an assay of the particles. Another object of the present inventionis to provide a device and method for separating particles according totheir composition, which pneumatically transports and separates theparticles during processing. Yet another object of the present inventionis to provide a device for separating particles according to theircomposition which is easy to manufacture, is simple to use and iscomparatively cost effective.

SUMMARY OF THE INVENTION

In accordance with the present invention, a device for separatingparticles according to their composition (i.e. a particle separator)includes a base member which includes various embedded channels.Specifically, the channels are provided for moving particles through thebase member. They include: an elongated central lumen, an air flowinjection channel, a particle injection channel, a diverter, and aplurality of particle recovery channels. As envisioned for the presentinvention, the various channels are connected in fluid communicationwith each other so that pre-crushed particles can be pneumaticallydriven through the channels of the base member. Structurally, all of thechannels have a characteristic dimension d_(L) that is less than twohundred fifty microns (d_(L)<250 μm). In the case of a circularcross-section, d_(L) is a diameter; and in the case of a rectangularshaped channel, d_(L) is a minimum distance between opposed sides.

For purposes of the present invention, the base member is asubstantially flat, rectangular-shaped structure, and it is made of atransparent material, such as plastic, quartz, borosilicate or sapphire.The elongated lumen, noted above, is formed in the central portion ofthe base member and it has a first end and a second end. The air flowinjection channel, also noted above, is formed in the base member toextend from the periphery of the base member for a connection in fluidcommunication with the first end of the lumen. Preferably, the air flowinjection channel is coaxially oriented with the lumen and, importantly,the air flow channel is formed with a junction point.

Also formed into the base member is a particle injection channel whichextends from the periphery of the base member for fluid communicationwith the junction point of the air flow injection channel. Additionally,a diverter is formed in the base member for fluid communication with thesecond end of the lumen. And further, an n-number of particle recoverychannels are formed into the base member for respectively establishingfluid communication from the diverter to the periphery of the basemember.

In an operation of the present invention, an air compressor is engagedwith the air flow channel to create a flow of air through the air flowinjection channel and into the central lumen. This air flow continuesthrough the central lumen in the base member at an over-pressure p_(o)that is greater than ambient pressure (e.g. 15 psig). A consequence hereis that the flow of air through the air flow injection channel isaccelerated to establish a venturi pump at the junction point.

A burst generator for creating bursts of particles is connected in fluidcommunication with the particle injection channel. The particleinjection channel also interconnects the burst generator with thejunction point on the air flow injection channel. Consequently, burstsof particles are sequentially drawn from the burst generator and throughthe particle injection channel by the venturi pump at the junctionpoint, for further pneumatic transit through the central lumen.Importantly, in this operation, particles from the particle injectionchannel are aligned for single file transit through the central lumenfor subsequent analysis. To assist with this alignment, the particleinjection channel can be formed with a microfluidic serpentine section.As envisioned for the present invention, each particle passing throughthe channels of the base member will have a unique diameter d_(p), whered_(p) is less than d_(L) (d_(p)<d_(L)).

Apart from the base member, the present invention includes an analyzerthat is positioned with the base member for monitoring the central lumenof the base member. Its purpose is to determine a size, and acomposition, for each particle as the particle transits through thecentral lumen. Structurally, the analyzer includes: a microcontroller, acamera, and a reflective spectrophotometer.

The camera of the analyzer is connected to the microcontroller forimaging each particle before it enters the lumen of the base member.Specifically, the image of the particle is used by the microcontrollerto calculate a size for the particle, which is based on d_(p). Thereflective spectrophotometer, which is also connected to themicrocontroller, is used for identifying the composition of eachparticle. In more detail, the reflective spectrophotometer includes abroadband light source for producing a light beam that is directed alonga first beam path toward the lumen in the base member. It also has agrating for receiving a return light beam which is caused by areflection of the light beam from a particle in the lumen. In thisinstance, the return light beam is directed toward the grating along asecond beam path to create a spectrum. A line image sensor is alsoprovided for capturing the spectrum of the return light beam for use bythe microcontroller in determining the composition of the particle. Inthis combination, the first beam path for the light beam is at an angleα relative to the second beam path of the return light beam, where α isless than 90°. Thus, in its operation, the microcontroller analyzes thesize of each particle together with the composition type of the sameparticle.

After the particles have been analyzed by the microcontroller, a sorteris provided to pneumatically separate the particles according to theircomposition. In detail, the sorter includes an n-number of gate valvesthat are mounted on the base member. Further, each gate valve isconnected in fluid communication with a respective particle recoverychannel. Thus, each gate valve is interconnected in fluid communicationwith the diverter.

An n-number of collection bins are individually connected with arespective particle recovery channel for receiving all particles havinga predetermined same composition. To do this, depending on the particlecomposition, the microcontroller simultaneously opens one gate valve andcloses the remaining (n−1) gate valves. This action then selectivelydirects particles of the same composition toward the open gate valve andinto its associated collection bin. An assay of the particles can thenbe made.

For another embodiment of the present invention, it is to be appreciatedthat a plurality of devices can be simultaneously employed incombination. The objective here for using a combined plurality ofdevices is, of course, to increase the system throughput. In particular,the present invention envisions that a large number of devices can beoperationally integrated to process as much as one ton of material (i.e.particles) in an hour.

In another aspect of the present invention, it is to be appreciated thatby using a device of the present invention, a relatively minute trace ofa target mineral can be detected in a very large sample of material(particles). Importantly, the detection of such a small amount of thetarget material may well justify additional assays.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features of this invention, as well as the invention itself,both as to its structure and its operation, will be best understood fromthe accompanying drawings, taken in conjunction with the accompanyingdescription, in which similar reference characters refer to similarparts, and in which:

FIG. 1 is a schematic presentation of the operational components of adevice for separating particles in accordance with the presentinvention;

FIG. 2 is a top plan view of the base member of the present inventionshowing various particle channels connected in fluid communication witheach other;

FIG. 3 is a view of the venturi pump established for the presentinvention, as shown by the line 3-3 in FIG. 2;

FIG. 4 is a view of the microfluidic serpentine established for thepresent invention, as shown by the line 4-4 in FIG. 2; and

FIG. 5 is a schematic presentation of an operational configuration forcomponents of the spectrophotometer of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

A system for sorting particles and preparing an assay in accordance withthe present invention is shown in FIG. 1 and is generally designated 10.As shown, the system 10 includes an injector unit 12, an analyzer 14,and a sorter 16. For purposes of the present invention, these componentscooperate to process and analyze an ore/mineral sample for thepreparation of an assay report 18 on the sample.

Structurally, an essential component of the system 10 is its base member20. This base member 20 is preferably made of a transparent material,such as quartz, glass, borosilicate, sapphire or a clear plastic, and itis bounded by a periphery 22. Importantly, various channels are embeddedin the base member 20 to establish fluid communication paths through thebase member 20.

Referring to FIG. 2, it will be seen that the base member 20 is formedwith an air flow injection channel 24 that extends from the periphery 22to a venturi pump 26. As shown, the venturi pump 26 is also formed inthe base member 20. Similar to the air flow injection channel 24, aparticle injection channel 28 also extends from the periphery 22 to theventuri pump 26. An elongated central lumen 30 then extends from theventuri pump 26 to a diverter 32. At the diverter 32, the central lumen30 divides into an n-number of particle recovery channels 34, of whichthe recovery channels 34 a-e are exemplary. As shown, the central lumen30 is coaxially aligned with the air flow injection channel 24, and thevarious particle recovery channels 34 a-e extend from the diverter 32 tothe periphery 22 of the base member 20. A window 36 is formed into thebase member 20 over the central lumen 30. Functionally, the window 36 isan area of the base member 20 which has a diminished thickness tofacilitate optical access to the central lumen 30.

As envisioned for the present invention, the air flow injection channel24, the central lumen 30 and the recovery channels 34 a-e will all havea characteristic dimension d_(L). In general, d_(L) will be less thanaround two hundred fifty microns (d_(L)<250 μm). On the other hand, theparticle injection channel 28 has a characteristic dimension d_(Lp),where d_(Lp) will be less than about 150 microns (d_(Lp)<150 μm).Further, the cross-section of each channel 24, 28 and 34, and centrallumen 30, may be either circular or rectangular. In the case of acircular cross-section, d_(L) will be the diameter of the channel. Inthe case of a rectangular cross-section, d_(L) will be a minimumdistance between opposed sides of the channel.

Returning to FIG. 1, it will be seen that the system 10 includes aparticle source 38, such as a hopper, for feeding pre-crushed particlesof a sample ore/mineral into the system 10. As shown, the particlesource 38 is connected to the burst generator 40 of the injector unit12. It will also be seen that the injector unit 12 of system 10 includesan air compressor 42. For the system 10, the burst generator 40 isconnected to the particle injection channel 28 by a solenoid valve 44,and the compressor 42 is connected to the air flow injection channel 24by a solenoid valve 46. Further, both FIG. 1 and FIG. 2 show that nearthe solenoid valve 44, at the periphery 22 of the base member 20, theparticle injection channel 28 is formed with a microfluidic serpentinesection 48.

In detail, the venturi pump 26 is shown in FIG. 3 to effectively drawparticles 50 from the particle injection channel 28 into the centrallumen 30 of the base member 20. As is well known in the pertinent art,this pneumatic function is a result caused by pressure differentials ina fluid flow. Specifically, in the case of the present invention, thecompressor 42 creates an over-pressure, p.sub.o, in the air flowinjection channel 24 that causes accelerated air to flow from the airflow injection channel 24 into the central lumen 30. As this air flowpasses through the venturi pump 26, its higher velocity relative to airin the particle injection channel 28 causes a relatively lower pressurein the air flow injection channel 24. This pressure differential thendraws particles 50 from the particle injection channel 28 into theventuri pump 26 for further transport through the central lumen 30. Asshown in FIG. 3, the particle injection channel 28 approaches the airflow injection channel 24 at an angle of approximately 45 degrees. Theparticle injection channel 28 is connected in fluid communication to theair flow injection channel 24 at the venturi pump 26 at an angle ofapproximately 20 degrees.

Still referring to FIG. 3, for a detailed consideration of the venturipump 26, it will be seen that various channels in the base member 20have different characteristic dimensions. In particular, FIG. 3 showsthat the air flow injection channel 24, and the central lumen 30, bothhave a substantially same diameter, d_(L). On the other hand, theparticle injection channel 28 and the venturi pump 26 at the juncturebetween the air flow injection channel 24 and the venturi pump 26 eachhave a diminished diameter d_(Lp). Specifically, d_(Lp) is approximately150 μm and is less than d_(L) which is approximately 250 μm(d_(L)>d_(Lp)). The consequence here is that the velocity of airentering the venturi pump 26 from the air flow injection channel 24 isincreased because d_(L)>d_(Lp). A further consequence of this is thatthe pressure differential in the venturi pump 26 is also increasedbecause of the air velocity increase in the venturi pump 26.

In the action described above for the venturi pump 26, two factors areof particular importance. For one, the over-pressure p_(o) generated bythe compressor 42 needs to be above the ambient pressure. For the other,each particle 50 needs to have an effective diameter, d_(p), which isless than the characteristic dimension d_(Lp) disclosed above for theparticle injection channel 28 (d_(p)<d_(Lp)). This latter requirementcan be satisfied by incorporating an appropriate mesh screen with theparticle source 38 that will reject particles 50 which exceed thepre-determined d_(p).

In FIG. 4 it is anticipated that as particles 50 enter the particleinjection channel 28, from the burst generator 40 (not shown in FIG. 4)through the solenoid valve 44, it may happen they will do so in clumps.To help in separating the particles 50 from each other, a microfluidicserpentine section 48 can be formed into the particle injection channel28. The intended consequence here is that the tortuous route which iscreated will cause collisions between the clumped particles 50 and wallsof the microfluidic serpentine section 48. These collisions can thenassist in separating the particles 50 from each other. This separationis important. As intended for the present invention, and bestappreciated with reference to FIG. 3, an important aspect of the presentinvention is that all of the particles 50 are aligned in single file asthey pass through the central lumen 30. As shown in FIG. 4, themicrofluidic serpentine section 48 comprises multiple obtuse-angledbends in the particle injection channel 28 having a generally sinusoidalform and bumps on the segments between each bend of the particleinjection channel 28.

Returning to FIG. 1 it will be seen that the analyzer 14 of the system10 includes a microcontroller 52. Further, a camera 54 and aspectrophotometer 56 are connected directly with the microcontroller 52.Also, as shown in FIG. 1, the spectrophotometer 56 includes a lightsource 58, a sensor 60 and a grating 62. In their combined cooperation,the camera 54 and the spectrophotometer 56 are controlled by themicrocontroller 52 to measure and analyze each individual particle 50 asit passes through the central lumen 30. In detail, the camera 54 willtake a picture of each particle 50 that is then used by themicrocontroller 52 to determine a size for the particle 50. Typically,this measurement of particle 50 will be accomplished before the particle50 enters the central lumen 30. Then, after its size is determined, thespectrophotometer 56 is activated to determine a composition of theparticle 50.

FIG. 5 shows the components of spectrophotometer 56 in a typical,operational configuration. As shown, it is to be appreciated that theparticle 50 is transiting through the central lumen 30. During thistransit, the light source 58 directs a beam of light along the beam path64. Light that is reflected from the particle 50 will then return fromthe particle 50 along another beam path 66. The angle α between beampath 64 and beam path 66 will preferably be an acute angle in the rangebetween 45° and 60°. Positioned on the beam path 66 is the grating 62which is used to spread light reflected from the particle 50 into aspectrum 68. Then, using techniques well known in the pertinent art, thesensor 60 can analyze the spectrum 68 to determine the composition ofthe particle 50.

In FIG. 1, along with the diverter 32 and the particle recovery channels34 a-e, the sorter 16 is shown to include a plurality of solenoid valves70 a-e (only solenoids 70 a and 70 e are designated in FIG. 1).Nevertheless, as shown, each solenoid valve 70 a-e is connected betweena respective particle recovery channel 34 a-e and a collection bin 72a-e. Further, for reasons set forth below, the solenoid valves 70 a-eare each individually connected with the microcontroller 52 for theirseparate activation. For purposes of this disclosure, it is to beappreciated there can be an n-number of particle recovery channels 34 inthe sorter 16, with a corresponding n-number of solenoid valves 70 andcollection bins 72. The number 5 for “n” as used in this disclosure ismerely exemplary. Moreover, it is to be appreciated that although thebase member 20 may be formed with an n-number of particle recoverychannels 34, not all of the channels 34 need to be used for preparingthe assay report 18.

Prior to an operation of the system 10 of the present invention, auser/operator (not shown) will use a keyboard 74 for inputting desiredoperational parameters to the microcontroller 52. For example, it mayhappen that the user/operator is interested in ascertaining the contentof gold (Au) in a given sample of an ore/mineral. Further, consider theuser/operator wants the gold particles 50 to be collected in collectionbin 72 a, with all other particles 50 being sent to the collection bin72 e. In this example, the fact that gold (Au) is to be investigated,the selection of collection bin 72 a for this collection, the operationof burst generator 40, and the over-pressure p_(o) that is selected forcompressor 42, are all typical inputs for microcontroller 52.

In an operation of the system 10, the compressor 42 is activated and thesolenoid valve 46 is opened to admit compressed air at an over-pressurep_(o) into the air flow injection channel 24. Burst generator 40 is alsoactivated and the solenoid valve 44 is pulsed to allow predeterminedbursts of pre-crushed particles 50 into the particle injection channel28. The particles 50 are then drawn into alignment by the venturi pump26 for transit through the central lumen 30 in single file. Duringtransit of the particles 50 through the central lumen 30 they are sizedusing images taken by the camera 54, and their composition is determinedby the spectrophotometer 56. After passing through the central lumen 30,each particle 50 is directed to a specific collection bin 72 a-e,according to its composition. In the example given here, gold particles50 are pneumatically directed by the diverter 32 into the collection bin72 a. Specifically, this pneumatic direction of gold particles 50 isaccomplished by opening the solenoid valve 70 a, while closing all ofthe other solenoid valves 70. On the other hand, the remaining particles50 (i.e. non-gold) are pneumatically directed into the collection bin 72e by opening the solenoid valve 70 e while the solenoid valves 70 a-dare closed. It is envisioned for the present invention that theparticles 50 may be native gold, native silver, acanthite, chalcopyrite,sphalerite, and rare earth minerals such as bastnasite, monazite andxenotime. As will be appreciated by the skilled artisan, this selectivedirection of particles 50 through the diverter 32 can be accomplishedunder computer-control, in accordance with input provided by theuser/operator.

While the particular Universal Mineral Separator as herein shown anddisclosed in detail is fully capable of obtaining the objects andproviding the advantages herein before stated, it is to be understoodthat it is merely illustrative of the presently preferred embodiments ofthe invention and that no limitations are intended to the details ofconstruction or design herein shown other than as described in theappended claims.

What is claimed is:
 1. A pneumatic device for separating particlesaccording to their composition which comprises: a source of pre-crushedparticles, wherein each particle has a unique diameter d.sub.p; a basemember made of a transparent material and formed with an elongated lumenextending through the base member, wherein the lumen has a first end anda second end, with a cross-section having a characteristic dimensiond.sub.L approximately 250 microns, and further wherein d.sub.p is lessthan d.sub.L (d.sub.p<d.sub.L)), wherein, for a circular cross-section,d.sub.L is a diameter, and for a rectangular shaped channel, d.sub.L isa minimum distance between opposed sides; an injector unit, including apneumatic venturi pump connected in fluid communication with the firstend of the lumen in the base member for pneumatically injecting aplurality of separated particles for single file transit through thelumen, wherein the injector unit comprises: a compressor for creating anair flow through the lumen in the base member; an air flow injectionchannel formed into the base member to connect the compressor in fluidcommunication with the first end of the lumen in the base member, forpneumatically injecting the particles into the lumen through the firstend thereof at an over-pressure p.sub.o greater than ambient pressure; aburst generator mounted on the base member and connected between thesource of pre-crushed particles and the base member for creating burstsof particles; and a particle injection channel formed into the basemember for connecting the burst generator in fluid communication withthe air flow injection channel at a junction point, wherein the particleinjection channel is connected to an airflow injection channel at anacute angle, and wherein the creation of air flow through the air flowinjection channel by the compressor establishes the venturi pump at thejunction point for sequentially drawing particles in the bursts from theburst generator, and through the particle injection channel for furtherpneumatic transit through the lumen; an analyzer positioned with thebase member for monitoring the lumen of the base member to determine asize, and a composition for each particle, as the particle transitsthrough the lumen; and a sorter connected in fluid communication withthe second end of the lumen in the base member for pneumaticallydiverting each particle from the lumen and into a predeterminedcollection bin for separation of the particles according to thecomposition of the particle.
 2. A device as recited in claim 1 whereinthe particle injection channel includes a microfluidic serpentinesection located between the particle burst generator and the junctionpoint to align the particles in single file, the microfluidic serpentinesection comprising multiple obtuse-angled bends in the particleinjection channel and a segment between each bend, wherein each segmenthas at least one bump.
 3. A device as recited in claim 1 wherein theanalyzer comprises: a microcontroller; a camera connected to themicrocontroller for imaging each particle before the particle enters thelumen of the base member, wherein the image of the particle is used bythe microcontroller to calculate a size for the particle; and areflective spectrophotometer connected to the microcontroller foridentifying the composition of each particle, wherein themicrocontroller analyzes the size of each particle together with thecomposition of the same particle to prepare an assay report.
 4. A deviceas recited in claim 3 wherein the reflective spectrophotometer furthercomprises: a light source for producing a light beam directed along afirst beam path toward the lumen in the base member; a grating forreceiving a return light beam, wherein the return light beam is causedby a reflection of the light beam from a particle in the lumen, andwherein the return light beam is directed toward the grating along asecond beam path for creating a spectra; and a line image sensor forcapturing the spectra of the return light beam for use by themicrocontroller in determining the composition for the particle.
 5. Adevice as recited in claim 4 wherein the beam path for the light beam isat an angle .alpha. relative to the beam path of the return light beam,and wherein .alpha. is less than 90.degree.
 6. A device as recited inclaim 1 wherein the sorter comprises: a diverter formed into the basemember at the second end of the lumen; an n-number of gate valvesmounted on the base member; an n-number of particle recovery channelsformed into the base member for interconnecting the diverter in fluidcommunication with a corresponding gate valve; and an n-number ofcollection bins, wherein each collection bin is individually connectedwith a particle recovery channel for receiving particles having apredetermined same composition type.
 7. A device as recited in claim 6wherein the microcontroller simultaneously opens one gate valve andcloses the remaining (n−1) gate valves to selectively direct particlesof the same composition type toward the open gate valve and into itsassociated collection bin.
 8. A device as recited in claim 7 wherein thecomposition type is a mineral selected from the group consisting ofnative gold, native silver, acanthite, chalcopyrite, sphalerite,bastnasite, monazite and xenotime.
 9. A device as recited in claim 1wherein the particle source comprises: a hopper for receiving thepre-crushed particles; and a mesh for receiving a sample of particlesfrom the hopper to remove oversized particles from the sample forrecycling when a particle has a diameter greater than d.sub.p.
 10. Adevice as recited in claim 1 wherein the particle injection channel hasa characteristic dimension d.sub.Lp, where d.sub.Lp is approximately 150microns.
 11. A method for using a pneumatic device to separate particlesaccording to their composition which comprises the steps of:pre-crushing a mineral sample into a plurality of individual particles,wherein each particle has a unique diameter d.sub.p; injectingcompressed air into a base member at an over-pressure p.sub.o greaterthan ambient pressure for moving air through an air flow channel and alumen formed into the base member, wherein the lumen has a first end anda second end, with a cross-section having a characteristic dimensiond.sub.L approximately 250 microns, wherein the air flow channel isconnected in fluid communication with the first end of the lumen andfurther wherein d.sub.p is less than d.sub.L (d.sub.p<d.sub.L), wherein,for a circular cross-section, d.sub.L is a diameter, and for arectangular shaped channel, d.sub.L is a minimum distance betweenopposed sides; drawing the particles into a particle injection channel,wherein the particle injection channel is formed into the base member influid communication with the air flow injection channel at a junctionpoint, the particle injection channel connected to an airflow injectionchannel at an acute angle, wherein the creation of air flow through theair flow injection channel by the compressor establishes a pneumaticventuri pump at the junction point for pneumatically drawing particlesin single file through the particle injection channel for furtherpneumatic transit through the lumen, the particle injection channelhaving formed therein a microfluidic serpentine section comprisingmultiple obtuse-angled bends in the particle injection channel and asegment between each bend, wherein each segment has at least one bump;imaging each particle with a camera before the particle enters the lumenof the base member, wherein the image of the particle is used by amicrocontroller to calculate a size for the particle; identifying thecomposition of each particle during a transition of the particle throughthe lumen, wherein particle identification is accomplished by themicrocontroller using a reflective spectrophotometer connected to themicrocontroller; and pneumatically diverting individual particles bymicrocontroller control from the second end of the lumen through aselected one of an n-number of particle recovery channels and to acorresponding gate valve mounted on the base member, wherein thediversion is accomplished according to the composition type of theparticle as determined during the identifying step, and wherein ann-number of respective collection bins are individually connected with agate valve and a respective particle recovery channel for receivingparticles having a predetermined same composition type.
 12. A method asrecited in claim 11 wherein the diverting step is accomplished by themicrocontroller simultaneously opening one gate valve while closing theremaining (n−1) gate valves to selectively direct particles of the samecomposition type toward the open gate valve and into its associatedcollection bin.
 13. A method as recited in claim 11 wherein the particleinjection channel has a characteristic dimension d.sub.Lp, whered.sub.Lp is approximately 150 microns.